The new Surgeon General's Report (SGR), Preventing Tobacco Use Among Youth and Young Adults, highlights the addictive nature of nicotine and emphasizes the need for effective and accessible cessation treatment for the more than 3.6 million youth who smoke. This application is in response to PA-13-078, Behavioral and Integrative Treatment Development Program (R34), which supports the development and testing of behavioral interventions targeting substance abuse, including studies focused on Intervention generation and refinement (Stage IA), and pilot or feasibility (Stage IB), and research designed to increase implementability of interventions with creative use of technology. We have developed Craving to Quit (C2Q), a smartphone intervention for smoking cessation for adults that integrates mindfulness training (MT) into a smoking cessation curriculum. While MT has been shown to be efficacious for smoking cessation in adults, it has not been tested in adolescents. In addition, dissemination of MT is challenging due to the need for experienced MT therapists, high time demand, difficulties in scheduling sessions, and high costs of in-person treatment delivery. Mobile, smartphone technologies provide a promising medium for overcoming these barriers to dissemination. We propose to adapt and refine our existing Craving to Quit (C2Q) app for use by adolescent smokers (Stage IA), and to conduct feasibility and pilot testing (Stage IB) in preparation for an R01 application to definitively test efficacy and probe psychological mechanisms of change resulting from MT. In the pilot test, six public high schools will be randomly assigned to one of three conditions, two schools per condition: (1) C2Q-Teen app (smoking cessation delivered through a smartphone app via MT), (2) NCI's QuitSTART app designed for teen smokers (NCI-QS) (smoking cessation delivered through a smartphone app without MT), or (3) written smoking cessation materials only (MO). One hundred forty four adolescent smokers interested in quitting will be recruited (24/school, 48/condition). School nurses will introduce the three interventions in the school setting. Our firs primary aim is to adapt the C2Q app for use by adolescent smokers (C2Q-Teen). Our second primary aim is to evaluate the feasibility and acceptability of the interventions to ensure adequacy of each intervention for a larger RCT designed specifically to compare efficacy rates. Secondary aims are to assess relative efficacy of the three interventions and independent contributions of smartphone intervention delivery and mindfulness in increasing cotinine-validated 7-day point prevalence abstinence at 3- and 6-month follow-up in order to adequately power a larger trial, and to determine the relationship between C2Q-Teen usage and abstinence. If eventually found to be effective, C2Q-Teen offers an innovative and potentially powerful intervention for supporting teens in their efforts to quit that would be relatively easy t disseminate widely and have tremendous public health significance, addressing the SGR's call for readily available treatment for adolescent smokers wanting to quit.